Spring tester



ApriH9,194-9. I SMITH 2,457,539

SPRING TESTER Filed July 51, 1944- I N V EN TOR. f/omqza l7 Snmv Patented Apr. 19, 1949 UNITED STATES PATENT OFFICE This invention relates to a spring tester. In the testing of springs, such, for example, as helical coil wire springs, it is common practice to place them under several different loads and measure their length for each load. In fact,

the user of the spring usually specifies his standards as to the length of the spring under diiierent loads which the manufacturer must meet. For example, the specification might require the coil spring to be two inches lon under no load, an inch and a half plus or minus a few thousandths of an inch under a load of one pound, and an inch and a quarter plus or minus a few thousandths of an inch under a load of two pounds. In such case it is highly desirable to have a spring tester in which the length of the spring under these different loads can be accurately, expeditiously and simply tested by the ordinary unskilled operator.

It is the object of this invention to produce a machine for accurately, expeditiously and simply testing springs for length under a plurality of varying loads and which is capable of operation by ordinary unskilled labor.

Fig. 1 is an elevation of my machine with the as to length under varying loads.

Fig. 2 is a detail showing the position of a portion of the apparatus where the spring is being tested for length under an increased or plural load.

Referrin more particularly to the drawings it Will be seen that my machine comprises a base l, a pair of upright members 2 upon whicha scale beam 3 is supported by a pair of knife edge pivots 4 supported upon conventional agate sockets. The scale beam 3 has slidably mounted thereon a weight 5 which can be locked in position on the beam by the set screw 6.

A platform I having a flat planar face 8 is pivotally supported adjacent one end of beam 3 by a standardized type of scale beam suspension on knife edges 9. Platform 1 has its upper face 8 always maintained level or horizontal by a parallelogram arrangement comprising links I!) and II pivoted together with a ball bearing pivot as at l2. Links II are pivotally mounted on uprights 2 by ball bearing pivots l3 perpendicularly below knife edge pivots 4. Links 10 are fixed to platform 1. Thus, at all elevations to which the platform I is pivoted, upper surface 8 will always remain horizontal or level due to the well-known parallelogram action oflinks l and H which cooperate with the beam 3 and uprightsl. In this well-known parallelogram action links ID will always be parallel to a line passing through Claims. (Cl. 73-161) spring in position preparatory to testing the Samej.j

- the dial indicator will read zero.

pivots 4 and i3 and links II will always be parallel to a line passing through pivots 4 and 9.

A cylinder I4 which houses plunger I5 is adjustably mounted upon post It by means of collar l'l. Post I6 is supported on frame I. Plunger I5 is arranged to be raised and lowered by means of a rotary shaft l8 provided with a crank handle l9. Plunger I5 is provided with a rack along one face which meshes with a gear fixed on shaft I8 within cylinder housing l4 so that turning of shaft It by handle I9 in a conventional manner will raise or lower plunger I5.

A conventional gauge or dial indicator 20 is mounted on the lower end of plunger I5 by bracket 2|. The lower end of indicating plunger 22 contacts an abutment or gauge block 23 fixed on the horizontal face 8 of platform I. A gauge block 24 is also mounted on platform 7 to serve as a support for the lower end of the spring 25 which is being tested. Thus, as crank handle I9 is turned to lower plunger l5 to thereby compress spring 25, the decrease in length of sprin 25 is accurately recorded on the dial indicator 20.

The opposite end of the scale beam 3 has a bracket 25 pivoted thereon by pin 21. Handle 28 in the form of an inverted U passes through bracket 26 and supports at its lower end a secondary weight support 29. The Weights are referenced 30. Bracket 26 is provided with a pin 3i which has a lost motion connection with handle 28 so that after the beam 3 is elevated a certain distance pin 3| will pick up handle 28, support 29 and Weights 30. Platform l is provided with a rest 32 which supports the weights 30 and their supports 29 when not in use.

For purposes of description but not by way of limitation, my spring tester is shown for testing the length of a coil spring under two different loads. However, if desired, I can use my apparatus for testing the lengths of a spring under any number of diiferent loads by adding additional weight pick up arrangements, such as above described.

The operation of the device is as follows: Assuming that one is testing the spring above referred to, cylinder housing l4 will be adjusted and locked in position on post l6 so that spring 25 can be placed upon block 24 and the plunger [5 lowered into contact with the upper end of the spring without loading sprin 25 and so that the dial plunger 22 will just contact block 23 and Weight 5 will the beam 3 will balance. An additional half pound weight will be placed upon support 29. Handle (9 will now be turned to lower plunger l until a load of one pound is imposed upon spring 25 and beam 3 will be in balance. At this time, if the spring meets specifications, the dial indicator should read one and a half inches. The plunger I5 is now lowered further to impress a greater load on spring 25 until the additional onehalf pound dead weight is picked up by bracket 26 at the end of the scale. The spring will now be under a load of one and one-half pounds and if it meets the required standard, the indicator will read one and one-quarter inches.

If desirable, a third or any additional number of weights could be picked up consecutively by still further compressing spring 25 and causing further travel of the beam to obtain additional load length tests of the sprin With the apparatus set up as indicated, the operator simply inserts a spring 25 upon block 24 with the plunger IS in raised position and then turns handle 19 until the beam balances for weight 5 and then reads the dial indicator for the length of the spring under its first load, and then the operator turns the handle still further until the additional weights '30 are picked up whereupon the dial indicator is read for the second length of the spring under loads consisting of the sliding weight =5 and the dead weight 30. Thus, it will be seen that a coil spring can be tested on my apparatus for length under different loads efliciently, simply and quickly by one requiring no special skill.

I claim:

1. A spring tester for testing the length of a spring under different loads comprising in combination a pivoted beam, 2. support for the spring being tested mounted on the beam on one side of the pivot, means opposite said support and movable towards said support to apply pressure on said spring and compress the spring between said means and the support, said beam being arranged to pivot as pressure is applied on said spring, a plurality of difieren-t resistance means arranged to be consecutivelyapplied to the pivoted beam on the other side of the said pivot as the beam pivots in one direction, an operative connection between the first of said resistance means and said beam whereby said first resistance means immediately opposes movement of the beam upon the application of said pressure upon said spring and support, a lost motion connection between another of said resistance means and said beam whereby said other resistance means opposes movement of the 'beam after the pressure applied against "the spring exceeds the counterpressure exerted "by said first resistance means and whereby the spring is loaded consecutively and cumulatively with a plurality of different loads, and means operatively "connected to said support and pressure applying means for indicating the length of the spring for each of the diiTerent loads.

2. A spring tester for testing "the length of a spring under different loads comprising in combination a pivoted'beam, a support pivoted on'the beam on one side of the-beam pivot, a plurality of difierent resistance means arranged to consecutively apply a load on the beam on the opposite 'side of the beam pivot, a plunger opposite said pivoted support and movable toward saidsupport to apply pressureonsa'id springand compress the spring between the plunger and the support 'to diiferent lengths as the different resistance means beam, said beam being arranged to pivot as pressure is applied on said spring, an operative connection between the first of said resistance means and said beam whereby said first resistance means immediately opposes movement of the beam upon the application of said pressure upon said spring and support, a lost motion connection between another of said resistance means and said beam whereby said other resistance means opposes movement of the beam after the pressure applied against the spring exceeds the counter-pressure exerted by said first resistance means and means for indicating the length of the spring for each of the different loads.

3. A spring tester for testing the length of a spring under different loads comprising in combinatlon a pivoted beam, a support for the spring being tested mounted on the beam on one side of the beam pivot, a plunger arranged to contact an end of the spring and movable toward said support to compress said spring and simultaneously pivot said beam, a weight mounted on the beam on the side of the beam pivot opposite to said support, and at least one additional weight having a lost motion connection with the weight side of said beam and arranged to be picked up by the beam after the pressure applied against the spring by the plunger exceeds the counter-pressure exerted by the weight on said arm whereby the spring is subjected consecutively and cumlatively to a plurality of different loads, and dial indicating means mounted between the plunger and the spring support for indicating the length of the spring for each of the difierent loads whereby upon a single stroke of said plunger in one direction the difierent lengths of said spring under different loads can be ascertained 4. A spring tester comprising in combination a pivoted beam, a support mounted on said beam on one side of the pivot :tor said beam, said support being adapted to contact the spring being tested at one end, means opposite said support adapted to contact the other end of the spring and-movabletowardsaid support to compress said spring and simultaneously pivot said beam, 2. Phirality of weights on the opposite side of the pivot for :said beam arranged to consecutively and cumulatively .add their weight to the weight side of the 'beam to thereby apply tdiflerent loads to said spring as the above-mentioned means moves toward said support, an operative connection between the first of aid weights and said beam whereby said first weight immediately opposes movement of the beam upon the application .of said pressure upon said spring and support, a lost motion connection between another of said weights and-said beam whereby said other weight opposes movement of the beam after the pressure applied against the sprin exceeds the counter-pressure exerted by said first weight and, indicating means for indicating the length of the spring under such difieren't loads whereby upon a single stroke of said plunger in 'one direction the different lengths of said spring under different'loadscanbeascertained.

5. A spring tester comprisingin combination a pivoted beam, a platform pivotally mounted on the rbeam on one side of 'the beam pivot, a parallelogram linkage connected to said support for keeping the same horizontal as the beam pivots,

-a plunger movable toward and away from said support, the said spring to be-testedbeing mount- -ed between "the plunger and the spring support,

an adjustable weightvmounted onthe beam on the a w flt-ively and'cumulatively applied to the 5 opposite side or the beam pivot from the side on which the platform is mounted, at least one other weight having a lost motion connection with the weight side of the beam whereby as the plunger is moved toward the support the adjustable weight resists movement of the support and the spring is loaded and compressed and upon further movement of the plunger toward the support the second Weight is picked up by the beam and the spring is additionally loaded With a load equal to the resistance applied by both the first and second weights, and indicating means between the plunger and support for indicating the length of the spring under each of said difierent loads.

HOWARD M. SMITH.

REFERENCES CITED The following references are of record in the file of this patent:

5 UNITED STATES PATENTS Number Name Date 277,898 Harty May 22, 1883 1,510,218 Goodwin Sept. 30, 1924 10 1,992,987 Bilzer et al. Mar. 5, 1935 2,033,212 Walker Mar. 10, 1936 2,164,453 Gaskins July 4, 1939 FOREIGN PATENTS Number Country Date 100,853 Great Britain July 20, 1916 

